Question:medium
What is the mechanism of action of curare like drugs?
What is the mechanism of action of curare like drugs?
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Tubocurarine is a competitive antagonist at the nicotinic receptor.
Updated On: Jun 23, 2026
- Blocks ACh synthesis
- Blocks ACh receptors
- Persistent depolarization
- Agonistic with ACh receptors
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The Correct Option is B
Solution and Explanation
Step 1: Neuromuscular blockers are split into two groups. Non-depolarizing agents such as tubocurarine work by simple receptor competition, while depolarizing agents such as succinylcholine cause sustained end plate depolarization.
Step 2: Curare is the classic non-depolarizing agent. When given, it occupies the nicotinic receptor on the post junctional membrane without activating it, so released acetylcholine cannot bind and the muscle stays relaxed.
Step 3: Because the binding is competitive, increasing acetylcholine (for example with an anticholinesterase like neostigmine) can reverse the block, which confirms the receptor blocking action.
Step 4: Synthesis blockade (a), persistent depolarization (c, a feature of succinylcholine), and receptor agonism (d) are all incorrect descriptions. Curare blocks the ACh receptor.
\[\boxed{\text{Blocks ACh receptors}}\]
Step 2: Curare is the classic non-depolarizing agent. When given, it occupies the nicotinic receptor on the post junctional membrane without activating it, so released acetylcholine cannot bind and the muscle stays relaxed.
Step 3: Because the binding is competitive, increasing acetylcholine (for example with an anticholinesterase like neostigmine) can reverse the block, which confirms the receptor blocking action.
Step 4: Synthesis blockade (a), persistent depolarization (c, a feature of succinylcholine), and receptor agonism (d) are all incorrect descriptions. Curare blocks the ACh receptor.
\[\boxed{\text{Blocks ACh receptors}}\]
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